In using a map display device that reads out map data from a storage medium and performs a map display, there exists a region such that the map data stored in the map display device needs to be handled with care. For example, in some countries, it is prohibited to take out the map data stored in the map display device abroad; thus, when a vehicle having the map display device mounted thereon moves out of the country, it is necessary to prohibit a map display using the domestic map data.
To deal with such a region covered in a map that needs to be handled with care, Patent Document 1 discloses a map display device that can prevent itself from being taken out of a specific region in a state where the map data of the specific region can be read out. The map display device determines whether or not the current location is near the boundary of the specific region; if the location is judged near the boundary, the device displays a confirmation screen asking the user whether the readout of the map data stored in a memory device is disabled or not, and in response to a user's operation that permits disabling the readout of the map data, performs a process to disable the readout of the map data from the memory device. In this manner, the map display of the specific region can be locked near the border to prevent the user from unknowingly taking out the map data abroad in a state where the map is displayable.